Receiving device for distant-vision installation



April 3, 1928.

.G. VALENS] RECEIVING DEVICE FOR DISTANT VISION INSTALLATION 2 Sheets-Shoot 1 Filed Sept. '7. 1923 I I I I L- x mm www L @wN j'nkenrq/ Q Ka/erzsvf f April 3, 1928. 1,664,798

G. VALENSI RECEIVING DEVICE FOR DISTANT vIsIoN INSTALLATION Filed Sept. '7. 1923 2 Sheets-Sheet 2 Patented Apr. 3,1928. I I

.NITED STATES PATENT OFFICE.

Gnonens VALENSI, or rants, rnancn.

RECEIVING DEVICE FOR DISTANT-VISION INSTALLATION. Application filed September 7, 1923, Serial No. 661,507, and in France December 29, 1922.

The present invention relates to improve- With the same object in view, the invenments in receiving devices for distant vision tion also consists in providing at the receiv- 65 installations, that is devices adapted to reing station a luminous wide spot of uniform produce in half-tones, in lines, or in any or substantially uniform brightness over its 5 other structure, with or without colours Whole surface, the intensity of the illuminaand relief, the image of stationary or mov-- tion varying in accordance with the fiuctuaing objects explored at a remote transmittions of the photo-electric current, and in exting station. ploring such luminous wide spot, point by The installation is of the general type point, synchronously with the exploration at to wherein the object whose image is to be the transmitting station. The exploration of transmitted, is explored, point by point, at the object at the transmitting station and the the transmitting station, the light of the sucexploration of the luminous wide spot at the 05 cessive oint th l d ting up n a receiving station may thus take place with photo-electric cell which controls a photoldentical exploring devices, which may be 15 electric current The latter is transmitted readily synchronized, thus afiording a very by wire or wireless transmission to the reaccurate reproduction. ceiving tation where th i ag i to b r In order to increase the accuracy of the produced, F thi po th hot l reproduction, my invention has also for its tric current produces at the receiving staj ct to pr vide improved exploring means 20 ,tion, in a manner to be later described, a adapted to afford an exploration in a corn luminous point of variable brilliancy movinuous path, whereby a temporary and ing at a sufiicien't speed to provid fo the short lack of synchronism between the expersistence of the luminous impressions. ploring devices at the transmitting and re- The expldration at the transmitting station ceiving stations will not have a so much 25 d th p d ti f th image t, th edetrimental effect than heretofore, said exceiving station are synchronized by a synploring means being further adapted to atchronizing current transmitted by wire on ford an exploration at a uniform speed, wireless transmission. In the case of colour so as to accurately reproduce, in the whole andor relief reproductions, the image to be image, the tones and general appearance of transmitted is decomposed into several elethe object whose image is transmitted. Acmentary images by means of colour screens cording to my invention, said exploring and or a stereoscopic device, said elementary means embody preferably rotating opaque images being separately and synchronously discs having transparent lines formed with explored so as to act upon a corresponding portions of special spiral, affording the con- 35 number of photo-electric cells Each eletinuous exploration at uniform speed.

mentary image is transmitted and repro- In order to provide for a powerful illumiduced in'the manner above indicated and nation, and a great sensitiveness, my inventhe various images thus reproduced are retion further consists in generating electric combined into the final image in colour and rays in a tube containing a suitable gaseous or relief by means of coloured screens and material becoming illuminated when an elecor a stereoscopic device. trio current passes through the same. The

One object of the invention consists in discharge is produced between the electrodes providing a receiving plant adapted to afof the tube to which is applied the photoford a very true reproduction of the images electric tension, suitably amplified, in an amtransmitted from the remote transmitting plifier fed by the local source of energy. station, said images being however very The amplifier may be combined with the ilsharp and luminous, so as to be visible, if deluminating tube and in this latter case, the

sired for many persons at. the same time. discharge is produced by the current of the For this urpose, the photo-electric current, local source of energy and is controlled by which on ypossessesa small energy, is a-daptmodulating electrodes to which the photoed to modulate electric or electromagnetic electric tension is applied.

rays produced byia local source of energy, A further object of the invention consists which may be as strong as desired. in providing means for facilitating theelecembodying two rotating discs 104 and 105,v

tric discharge in devices embodying discharge tubes, so as to reduce as far as possible the priming potential.

The invention will be clearly understood with reference to the appended drawing which shows, by way of example, a number of embodiments of the invention, and in which:

Fig. 1 shows in a diagrammatical manner a complete installation for distant vision, according to the invention.

Fig; 2 is an elevational view of one embodiment of my exploring means.

Fig. 3 is a diagram illustrating another embodiment of the exploring means.

Fig. 4 is a diagram ofthe spiral transparent lines provided on the exploring members.

Fig. 5 shows at an amplified scale the path of exploration of an image.

Fig. 6 is a diagrammatical sectional view of a receiving plant, according to a modification.

Fig. 7 is a diagra'mmatical sectional view of a receiving plant, according to a further modification. I

Referring to Fig. 1, A denotes the transmitting station and B the remote receiving station. 101 is the object whose image is to be transmitted from station A to station B; said object is disposed in a chamber 102 and is strongly illuminated by lighting projectors 203 associated with condensers 204. The image of object 101, given by the objective lens 103, is explored by exploring means to be later described, and is formed preferably in the plane between said rotating discs. Said discsmask the whole image .of the object, except one point, which is moved in a continuous path and at a uniform speed. The small pencil of light which is allowed to pass beyond discs 104, 105 is directed through a collimator 108 over a photo-electric cell, for instance a potassium cell 109, contained in a metallic box 110 forming an electrostatic screen. The electrode of potassium 112 and the anode 111 are suitably connected to an amplifier 114, for example a three electrode lamp, fed by an electrical source 115 through a resistance 116in series with the amplifier plate. A battery 113 connected to electrode 112 (of 100 volts about) produces the photoelectric current. 117 denotes at protecting resistance. The variations in the intensity of the light acting upon the photo-electric cell produce corresponding variations in the photo-electric current, amplified by lamp 114, and the terminals 120 and 121 of the transmitting station have a corresponding varying potential difference.

The transmitting station further comprises a multipolar continuous current motor 106 fed by an electrical source 107. Disc 105 is keyed to the. motor shaft to which is through are connected to the respective rings 136, 137 whose brushes are connected to terminals 208, 209. Due to the special connection of rings 136, 137, with the armature, motor 106 operates as a small monophase commutating machine and is adapted for synchronizing purposes, as will be hereina er described.

Terminals 120, 121 of the photo-electric circuit are connected by a wire or wireless transmission to terminals 129, 130 of an amplifier 210 comprising several amplifying lamps 211 with the usual associated organs and by means of which the photoelectric current is suitably amplified. The amplified photo-electric current is supplied through leads 200, 201 to the modulating electrodes of an electric rays tube 122.

Tube. 122 is filled with a gaseous material and comprises a filament 124 heated by a battery 127 and an anode 126, which is under the tension of a local source of additional energy 128 of any suitable kind. The intermittent luminescence of the gaseous material, produced by the discharge between filament 124 and anode 126, is modulated by the photo-electric tension applied to the filav ment 124 and to an electrode 125 interposed 100 between filament 124 and anode 126 and produces a luminous wide spot of light of variable light intensity.

The luminous wide spot produced by tube 122 is explored, point by point, according 105 to the same continuous path and at the same uniform speed as the exploration at the transmitting station, by means of two discs 134,135, similar to discs 104,105. Disc 135 is keyed to the shaft of a motor no 106 identical with motor 106 and provided, as before, with a feeding source 107 and rings 136, 137*, connected to terminals 208, 209. Disc 134 is keyed to a counter-shaft 207 driven by gear wheels 205, 206*.

The synchronism in the rotation of the exploring means at both stations, that is the synchronism between motors 106 and 106 is obtained by the Poirsons arrangement, used in secret telephony. For this purpose the terminals'208, 209 are connected by a wire or wireless transmission to the terminals 208, 209.

The two motors will operate as an alternator and synchronous motor unit, coupled 125 at the said speed and phase; means may be provided whereby the two motors will be in constant mutual reaction and will act alternately as driven synchronous motors, (which will require a reversible wire or wireless connection), or else a given motor shall be always driven by the other, so that a nonreversible connection can be used. It is preferable to provide each motor with a suitable speed regulator of a known type. It will be understood that the luminous point visible to the eye located at 132 is moving according to the same path and at the same speed as the luminous point corresponding to the intersecting point of the transparent lines of discs 104;, 105; the speed of displacement being sufficient to secure the persistance of the luminous impressions on the retina, the image of the object 101 will be finally reproduced at the receiving station.

It will be seen that, due to the amplification, by means of amplifier 210 and the provision of a local source of additional energy 128, the energy of the photo-electric current flowing between terminals 120, 121, 129, 130, may be reduced to a minimum, that is to the order of magnitude of ordinary telegraphic or telephonic currents usually transmitted by lines or radio links, while the illumination of tube 122 is however sufiiciently powerful to afford a bright and sharp image.

In order to secure an exploration at uniform speed and according to a continuous path I prefer to rovide exploring means consisting of two iscs 13 1, 135 (Fig. 2) of opaque material but having transparent lines adapted to cross each other at a point moving along a zizgag continuous path a, a, a, a etc., such as illustratedin Fig. 5, and at a uniform speed. For this purpose, disc 135 is provided with a transparent line 212 made of two spiral arcs and disc 134 with a series of portions of spiral e f, fe

6, f f e ,'etc., of contrary directions. The shape of these spirals is shown at a larger scale in Fig. 4 and is analytically defined by the equation:

the spiral teeth. The two discs have the same diameter and are disposed in parallel and closely adjacent places in an orthogonal disposition; they are rotated about their axes at the same speed but in opposite directions. The intersecting point of their transparent lines will move over the square a b c d indicated in Fig. 5,

according to the path variable in front of the luminous spot of brilliancy.

It is evident that instead of using a screen havin 100 teeth and rotated in the direction contra ry to the other disc at 8 or more revolutions per second, I may use a screen with 10 teeth rotated at 80 revolutions per second, the other screen still rotating in the opposite direction at 8 revolutions per second.

It is evident also that other arrangements of discs such as 134 and 135, provided with such spiral arcs might be used in order to provide an exploration at a uniform speed according to the continuous path indicated in Fig. 5.

Similar movable screens will obviously be used for the exploration of the image to be transmitted and the reproduction of the same at the receiving station.

The same movable screens can also be used in the case of colour or relief reproduction, all being operated by the same power shaft; the two power shafts of the two corresponding stations are maintained in exact synchronism as concerns speed and phase due to the motors 106, 106* connected in the manner above indicated. 7

The exploring means may also consist of paper bands or photographic films provided with transparent broken lines upon an opaque background, corresponding to the lines shown in black upon a white background in Fig. 3. The first line may consist of 200 rectilinear elements inclined alter.

nately at 45 in either direction, so as to form 100 teeth whose width is double the height. The second line is formed by 'a single tooth which has the same height as the preceding teeth but whose length is 100 times greater. These opaque bands thus provided with transparent lines are moved athconstant speed at right angle to each ot er.

The modulation of the rays producedby I the local source of energy may be eifected by other means than those above indicated. In

the case of electromagnetic rays, the modulation may be obtained by the electromagnetic action of coils or condensers, to which the photo electric tension is applied. In the case of electric rays, the modulation is obtained by the control of' the-number, the speed or the pathof the electric particles, according to the nature and disposition of the rays generating electrodes and modulating electrodes.

The invention also contemplates the use of devices in which a liquid or gaseous luminescent substance is contained in a tube which is fitted as an electric rays generator, but in which said liquid or gas is separated from the rays producer by a thin wall permeable only to electrified particles.

However, I prefer to separate the receiver into two different tubes or sets of tubes, as explained with reference to Fig. 1. In the first set of tubes which forms an ionic or electronic relay (amplifier 210), the .electric rays produced bya local source of energy are modulated according to the varia- I be produced an alternating or undulating.

through.

tions of the photo-electric current from the transmitting station, and hence there will tension of considerable amplitude, e. g. several tens or even. several hundreds or sev-.

, form are invariable, but whose brilliancy will vary according to the fluctuations of the tension employed, that is, according to the fluctuations of the received photo-electric current, as above explained.

In other words the electrode 126 and the electrical sources 127 and 128 may be dispensed with. In such cases, the amplified photo-electric tension which is directly applied to electrodes 124, 126 produces by itself the electric discharge; the local source of additional energy herein consists of the sources of current feeding amplifier 210.

Alternatively, amplifier 210 may be dispensed with, and, in such case, the local source of additional energy is constituted only by the electrical source 128.

In practice, it is found necessary that the alternating or undulatory tension prevailing between the electrodes of the luminescent tube should have anamplitude which is dis tinctly greater or less than the priming potential in-thc case of a luminescent tube, (or

in the case of a tube containing a luminescent liquid, the pseudo-counter E. 'M. F.

which prevails between these electrodes). It

is therefore required, in order to avoid ex cessive amplification of the I'ECGIVGd photoelectric current, to reduce the priming potential of the luminescent tube as much as possible. For this purpose, I may employ tubes containing neon, helium or argon (or a suitable mixture of the three) and provided with suitable electrodes covered for instance with sodium or potassium. If desired, the electrodes can be illuminated by ultra-violet light, so that they will produce a. photo-electric disengagement of electrons and thus facilitate the discharge. The electrode may also consist of a hot filament 4 place in front of the anode, as in the Tungar rectifying tubes, so as to make use of a thermionic. discharge of electrons. Use can be made also, at the bottom of the luminescent tube and adjacent one ofthe electrodes, of anfauxiliary continuous current are in order to maintain the atmosphere in a slightly ionized condition and to facilitate I the discharge between the two main electrodes.

Obviously, the transformation into luminous energy of the energy of the electric rays produced by the local source of energy may be obtained in a manner diiferent from that above indicated and, namely, the luminescent gas may be replaced by a luminescent liquid or even by a screen of fluorescent solid material. A device embodying such a solid screen is shown in Fig. 6.

the latter being made of a perforated disc with numerous smallalined holes, in order to be protected againstthe impact of the positive ions which are directed towards the cathode through the holes of the grid. A screen 50 connected to the negative end of the filament, collects said positive ions and at thev same time limits their path, and consequently reduces the ionization of the gas in the neighborhoodof the electrodes. A battery 46 maintains the grid 45 constantly negative with regard to the filament, which affords the omission of a protecting screen beyond said filament, and hence to reduce to a minimum the distance between the grid and the filament. This results in the possibility of modulating the rays by' the use of an extremely small energy, for instance less than 1 microampere under a variation of tension of the grid of about 10 volts. A potentiometer 47 is mounted in series with or in opposition to the battery 46, and receives at its terminals 48 and 49,

by the filament 41 are set in motion by the l perforated anode 43 in the circuit of the source of electrical energy 44 and thus brought for instance to a potential of several hundreds of volts with respect to the filament. These electrons pass through the perforated anode 43 and form a divergent pencil which, due to'the suitable shapes and relative positions of the filament 41, grld 45 and anode 43, produces upon the fluorescent screen 52 fixed on the wall of tube 51, a wide luminous spot, whose surface is for instance of several sqluare centimeters, and havinga uniform bri liancy over its whole surface; This brilliancy is variable according to the potential of the grid with respect to the filament, i. e. accord ng to the photoelectric current proceeding from the transmitting station. Said luminous spot of variable brilliancy is observed through the exploring screens 53, 54.

The small tube 40 containing the filament and its screen, and the modulating grid may serve as a support for the anode. baid tube is located within the long tube 51 carrying the fluorescent screen 52.

Although I prefer to explore the luminous wide spot constituted by the luminescent material by means of the discs of Fig. 2, I may however perform the exploration by other means provided that said means afford an exploration at a uniform speed and according to a continuous path. For instance, I may produce with the luminous wide spot a fixed luminous point and I then displace the image of said point in a continuous manner and at a uniform speed by optical means operated electrically or mechanically. Said optical means (Fig. 7 consist of two mirrors 31, 32 (or two prisms, or the like) which are movable about suitable axes and are actuated by electrical or mechanical devices, or by like means. These mirrors may be mounted upon oscillographs or galvanometers supplied by alternators or generators of any kind producing an alternating E. Mr F. and driven or controlled by the motor 106 of the station and whose E. M. F. has theform of a wave corresponding to the'path of exploration chosen for the original image. The mirrors can also be mechanicall operated by the power shaft for instance y means of cams whose profile is also made to correspond to the chosen ath of exploration; the electric control and the mechanical cont-101 may also be used in combination.

This arrangement may be associated for example with a tube 26 provided with a solid fluorescent screen 25 which is illuminated bly a pencil of electric rays of short length. tube of this kind is advantageously provided with suitable means adapted to discharge the fluorescent substance and the walls, and to cause the negative charges to return to the anode. For this purpose the tube may contain a small amount of an ionized neutral gas, the electrodes 21, 23 which produce the electric rays (e. g. Wenhelt cathode and,perforated anode) being disposed if desired in a very small inner tube 20 so as to separate them 'from the gas contained in the main tube 26. Tube 20 thus constitutes a small cathode rays tube comprising an oxide-covered filament 21 (which can be protected by the screen 22), and the perforated anode 23. The cathodic'rays produced by the local source of additional energy 128 and modulated by the modulating electrode or electrodes 24 according to the fluctuations of the photoelectric current applied to terminals 200 and 201, will produce on the fluorescent screen 25, at the end of the outer tube v26, a luminous wide spot of variable brilliancy. An opaque screen 27 having a hole 28 can be used to suitably limit the outline of this spot. It is obvious 7. that I may use all methods of modulation, and that the modulating electrode or electrodes may occupy any desired position in the tubes 20 or 26.

The optical arrangement preferably contained in a camera 29, displaces the image of the luminous spot of variable brilliancy appearing through 28 in exact synchronism with the exploration of the original image. For this purpose the mirror 32 is attached to an oscillograph diagrammatically illustrated by the coil 30 and the larger mirror 31 is actuated by a cam 33. Mirrors 31 and 32 are respectively oscillated about an axis perpendicular to the plane of the figure and 88 about an axis parallel with the plane of the figure. The galvanometer or oscillograph controlling the mirror 32 is supplied by a.- current having a frequency of about 800 periods and whose wave-form (corresponding to the chosen path of exploration) has for instance the shape of a series of isosceles triangles, assuming that the exploring path is a sinuous line similar to that shown in Fig. 5. The outline of cam 33, which also corresponds to the exploration path, consistsof an indented cylindrical surface whose. generatrix is formed by spiral lines similar to those shown in Fig. 4 that is whose equation in polar co-ordinates p 0 has the linear 10 form =a6+b. The alternator (not shown supplying the galvanometer 30 and the sha t of cam 33 are driven by the main motor .106 of the station. The condenser 34 and objective 35 deflect the light pencil towards the 1 eye placed at 36, where the light pencil gives a moving image of hole 28.

In all the devices above described the eye may obviously be replaced by a photographic surface such as a sensitive plate or I]. a film in the case of tele-cinematography. In the case of colour reproduction, the elementary monochromatic images may be obtrained, as above indicated, by means of colour filters. However, use may also be Ill made of luminescent or fluorescent substances having respectively difl'erent colors.

Finally, the receiving plant may be combined with a transmitting plant. In-this case, motor 106 of the transmitting plant will be also motor 106 of the recelving plant, while the remote station will also have. a single motor 106, with both functions.

Having now described my invention, I declare that what I claim as new and desire to secure by Letters Patent is:

1. In a distant vision installation comprising a photo-electric cell at the transmitting station and an electric device at the reno ceiving station adapted to be acted upon by the photoelectric current proceeding from said photo-electric cell, a local source of additional energy for producing rays in said electric device, means in the path of said rays for producing 'a luminous Wide spot, means for acting upon said rays in accordance with the Variations of the photo-elec trio current, means for producing a luminous point from said luminous wide spot and ,for displacing said point in a continuous manner and at a uniform speed, and means for synchronizing said exploration with the exploration at the transmitting station of the image tobe reproduced.

2. A distant vision installation comprising a photo-electric cell for the transmission and a receiving electric device giving a fixed luminous wide spot, means for varying the intensity of said luminous wide spot in accordance with the variations of thephotoelectric current proceeding from said photoelectric cell, exploring means embodying two opaque adjacent discs of the same radius disposed above said fixed luminous wide spot and adapted to rotate at great speed, each of said discs being provided with a transparent line formed with portions of special spiral, the equation of said special spiral in polar coordinates p 6 related to the center of said disc being of the linear form =a+b0, and a motor rotating said discs in synchronism with the corresponding motor at the distant installation.

3. A'distant vision installation comprising a photo-electric cell at the transmitting station, the combination at the receiving station of a tube containing a gaseous material becoming illuminated when an electric current passes through the same,electric means for producing an electric dischargein' said tube, means for amplifying the photo-electric current proceeding from the photo-elecr tric cell, groups of electrodes within said tube andto which the amplified alternating ing .a photo-electric cell at the transmitting station, the combination at the receiving station of a tube containing a gaseous material becoming illuminated when an electric current passes through the same, electric means for producing an electric discharge in said.

tube, means for amplifying the photo-electric current proceeding from the photo-electric cell, groups of electrodes within said tube and to which .the amplified alternating tension is applied, means associated with said groups of electrodes and adapted to produce an auxiliary emission facilltating said electric discharge, means for exploring point by point the source of light constituted by said tube, and means for synchronizing such exploration with the exploration point by point at the transmitting station of the image to be reproduced.

5 A distant vision installation comprising a photo-electric cell at the transmitting station, the combination at the receiving station of an electric rays tube filled with a luminescent gaseous material, a local source of additional energy feeding said electric rays tube, means for modulating said electric rays in accordance with the variations of the photo-electric current proceeding from the photo-electric cell, means for exploring point by point the source of,

light constituted by the intermittent luminescence of said gaseous material and means for synchronizing such-exploration with the. 

